ReqMgr2 request validation fixed

-unittests passing
-reqmgr.py client script --all_tests passing
-ReqMgr2 convenience bash wrapper script added

@ticoann, please see the client script testing of ReqMgr2

dballesteros7 - I have removed default None definition of request arguments which caused problems later in spec validation ff they remained None (i.e. when they were not overwritten by user input arguments). I think more of those should eventually be removed from ReqMgr/DataStructs/Request.py but now everything passes - creating 10 various requests by the client script based on all available request templates.